leetcode Valid Parentheses(Java)

题目链接：点击打开链接

类型：数据结构

解法：创建栈数据结构

public class Solution {
    public boolean isValid(String s) {
    	if (s == null || s.length() < 1)
    		return false;
    	
    	Stack x = new Stack ();
    	for (char c : s.toCharArray())
    	{
    		if (c == '(')
    		{
    			x.push(')');
    		}
    		else if (c == '{')
    		{
    			x.push('}');
    		}
    		else if (c == '[')
    		{
    			x.push(']');
    		}
    		else if (x.isEmpty() || x.pop() != c)
    			return false;
    	}
    	return x.isEmpty();        
    }
}